If you invest in private markets, you'll receive Schedule K-1s instead of 1099s, and the difference is larger than it looks. A 1099 reports what you were paid. A K-1 reports your share of the entity's activity, whether or not you were paid anything.
That single distinction explains most of what confuses people about private investment taxation.
Why You Get One
Partnerships and LLCs taxed as partnerships don't pay federal income tax. Income, gains, losses, deductions, and credits pass through to the owners in proportion to their interests, and Schedule K-1 (Form 1065) is the document that reports your share.
Reading the Boxes
Part II — your identifying information and, in Item L, your capital account: beginning balance, contributions, current-year income or loss, distributions, and ending balance. Read this section every year. It's where you see whether the number you invested is still the number the sponsor thinks you have.
Box 1 — Ordinary business income (loss). Operating results. Usually where operating businesses, working interests, and lending activity land.
Box 2 — Net rental real estate income (loss). Typically where syndication results appear.
Box 5 — Interest income. Common in credit vehicles.
Boxes 8, 9a, 9b — Capital gains. Short-term, long-term, and collectibles (28%) respectively. Box 9b is where physical precious metals show up.
Box 13 — Other deductions. Includes management fees and other expenses allocated to you.
Box 19 — Distributions. Cash and property actually paid to you. This is not your taxable income — compare it to boxes 1 through 11 and the difference is the point of the next section.
Box 20 — Other information. A collection of coded items, several of which matter a great deal: Code V flags unrelated business taxable income relevant to retirement accounts, Code Z relates to the qualified business income deduction, and various codes carry state-specific information.
State schedules. Often attached separately. They drive nonresident filing obligations.
Phantom Income
The concept every private investor should understand before their first K-1 arrives.
You can be allocated taxable income you never received. The partnership earned it; your share is reported; the cash stayed in the entity — reinvested, held as reserves, used to pay down debt, or simply not distributed. You owe tax on it anyway.
This is normal and not a sign of anything wrong. But it means a private position can generate a cash outflow in a year it produces no cash inflow. If you hold several, the effect compounds. Reserve for it rather than being surprised by it.
The reverse also happens: a distribution can be non-taxable, treated as a return of capital that reduces your basis rather than income. Real estate syndications frequently work this way in early years because depreciation shelters distributed cash.
Why It Arrives Late
Partnership returns are due March 15, extendable to September 15. Your personal return is due April 15.
A K-1 arriving after April 15 is normal, especially in layered structures. An SPV can't complete its return until it receives a K-1 from the fund it invests in, which can't complete its return until it hears from its own holdings. Each layer adds delay, and the delay accumulates downward.
The practical response: plan to file an extension every year you hold private positions. An extension extends the time to file, not the time to pay — so you'll need to estimate. Ask the sponsor in Q1 for an estimate of your allocation, and ask before you subscribe what the sponsor's historical K-1 delivery timing has been. A sponsor that consistently delivers in August is telling you something about its administration.
Amended K-1s also happen, occasionally after you've filed. It's an annoyance, not a scandal.
Basis, and Why It Matters at Exit
Your basis starts with what you contributed, increases with allocated income and additional contributions, and decreases with distributions and allocated losses.
It governs two things: how much loss you can currently deduct (you generally can't deduct below zero basis), and your gain on exit. If you've received several years of non-taxable distributions that reduced basis, your taxable gain at sale is correspondingly larger. The tax that appeared to be avoided was deferred.
Track it yourself. The capital account in Item L is a useful reference but is maintained on the partnership's method, which may not equal your tax basis.
State Filings and Retirement Accounts
States. A partnership operating in a state you don't live in can create a nonresident filing obligation there. Some states require the partnership to withhold on your behalf; others offer composite returns that file for you. Ask which applies before you subscribe, particularly for oil and gas and real estate, where multi-state exposure is routine.
IRAs. Box 20 Code V is the one to watch. Debt-financed income and income from operating businesses inside an IRA can generate UBTI, which the IRA itself may owe tax on via Form 990-T — an outcome most investors don't expect from a tax-advantaged account. Leveraged real estate and leveraged credit funds are the usual sources.
None of this is tax advice. Take your K-1 to a CPA who has seen private partnership reporting before.
FAQ
Why did I get a K-1 instead of a 1099?
Because the investment is structured as a partnership, which passes income through to owners rather than paying tax itself.
Why do I owe tax on income I didn't receive?
Partnership income is allocated to you when earned, not when distributed. That gap is phantom income.
When should my K-1 arrive?
Partnership returns are due March 15 with extension to September 15. Layered structures routinely deliver after April 15.
Should I file an extension?
If you hold private partnership investments, generally yes. Extend to file, but estimate and pay what you owe by the deadline.
Do I have to file in other states?
Often, where the partnership operates in states you don't live in. Composite returns or withholding may handle it.
Can my IRA owe tax?
Yes, where UBTI is generated — commonly from debt-financed income. See Box 20, Code V.